The second part of the final consists of 29 multiple choice questions.
All questions are weighted equally. Page 8 of this exam contains a periodic
table and useful information. Additional information which may be required is
included with the particular problem. The answer sheet is the last page.
Remove it and complete the information listed. Write the letter indicating the
most correct answer to each of the 29 questions, clearly and carefully using
capital letters on the answer sheet. You need only turn in the answer sheet to
this examination.

1. A solution of 5.00 g of unknown X dissolved in 20.0 g of benzene freezes at
-4.52 ºC. Benzene normally freezes at 5.48 ºC and its kf is 5.12 ºC/m . What is
the unknown X?

4. An aqueous solution of ethylene glycol, C2H6O2, has a mol fraction of ethylene
glycol of 0.162. The molality of the same solution is,

A) 6.77 m
B) 6.77 m
C) 10.8 m
D) 16.2 m

FINAL EXAM PART 2 2

5. What is the activation energy of a reaction if the rate constant increases by a factor
of 10 when the temperature is raised from 303 K to 333 K.

A) 64 kJ
B) 46 kJ
C) 33 kJ
D) 30 kJ

6. The decomposition of NO

follows simple second order kinetics. In a particular experiment, it takes 2000
seconds for the concentration of NO to fall from 2.80 x 10-3 M to 2.00 x 10-3 M.
If a second experiment is performed with the initial concentration of NO at 0.0820
M, calculate how long it will take for the concentration to fall to 4.10 x 10-2 M.

8. A mixture of hydrogen and nitrogen are allowed to come to equilibrium at a
specified temperature according to the reaction,

Analysis of the equilibrium mixture shows that it contains 1.5 mol NH3, 2.0 mol
N2, 3.0 mol H2. How many moles of H2 were present at the beginning of the
reaction?

A) 3.0
B) 4.0
C) 4.5
D) 5.3

9. If the temperature is raised in an equilibrium system containing H2, N2, and NH3,
it is found that the equilibrium constant for the formation of NH3 decreases. This
indicates that the synthesis of ammonia from its elements

A) is exothermic.
B) is endothermic.
C) is impractical.
D) occurs without any change in energy.

10. The partial pressure of N2O is increased by

A) an increase in the volume of the container.
B) decreasing the temperature.
C) removing NO(g).
D) adding NO2(g).

11. Which value for an equilibrium constant, K, would indicate that the reaction

goes nearly to completion?

A) 1014 B) 10-14 C) 1
D) 0

FINAL EXAM PART 2 4

12. A white solid is known to be one of the following: K2C2O4, CaCO3, NH4NO3,
Ca(NO3)2. The substance is only slightly soluble in water. It dissolves readily in
HCl, releasing a gaseous product. What is the compound?

A) K2C2O4 B) CaCO3 C) NH4NO3 D) Ca(NO3)2

13. Which substance, when added to water, will not change the pH?

A) NaHCO3 B) NH4Cl
C) KCN
D) KCl

14. When 40.00 mL of 0.0900 M NaOH is diluted to 100 mL and 30.00 mL of 0.100
M HCl are added. The pH of the resulting solution is

A) 9.57
B) 11.66
C) 12.38
D) 12.18

15. At body temperature (98.6 ºF = 37 ºC), Kw has a value of 2.4 x 10-14. If the pH
of blood is 7.4 under these conditions, what is the concentration of OH-?

A) 1.0 x 10-7 M
B) 3.98 x 10-8 M
C) 2.51 x 10-7 M
D) 6.03 x 10-7 M

16. To prepare a buffer of pH = 3.2 equal concentration of a weak acid and its
conjugate base should be mixed together. The best acid for preparing such a
buffer would have a Ka of

A) 2.0 x 10-5 B) 6.0 x 10-4 C) 3.2 x 10-2 D) 4.0 x 10-6

FINAL EXAM PART 2 5

17. The pH of a 0.150 M Ca(OH)2 solution is

A) 0.523
B) 0.823
C) 13.5
D) 13.2

18. Propionic acid (Ka = 1.0 x 10-5) is titrated with a sodium hydroxide solution. In
order to most accurately determine the endpoint of the titration, which indicator
would be the best choice?

under standard conditions is +2.363 v. The pH of the solution in the cathode
compartment must be

A) 0
B) 1
C) 7
D) 10

28. Carbon monoxide is toxic to humans because

A) it reacts with water to form carbonic acid.
B) it is strongly basic.
C) it is a strong oxidizing agent.
D) it binds strongly to hemoglobin.

29. Which of the following statements about properties of oxygen, O2, is false?

A) Oxygen is a colorless, odorless, tasteless gas.
B) Oxygen is the only elemental form of oxygen.
C) Air is the primary industrial source for oxygen.
D) Oxygen is pale blue in both the liquid and solid phase.

FINAL EXAM PART 2 8

AP Chemistry by Satellite
Spring 1992
Final Exam Part 2
ANSWER SHEET

Student Name ______________________________

Teaching Partner's Name ______________________________

High School ______________________________

Date ______________________________

Write the letter indicating the most correct answer to each of the 29
questions, clearly and carefully using capital letters. Each question has
only one correct answer. Your score will be based on the number of
correct answers, so it is to your benefit to guess even if you are unsure of
the correct answer.